<div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">Could any of y'all help me with that? I have no experience at all with</div>

photodiodes; I mainly do web apps, not hardware, so I don't even know<br>
where to begin there.<br></blockquote><div> </div><div>I'd be up for laying out my understanding of a plan of attack; other people who've looked at analog components more recently could make better recommendations on part numbers. Let me know off-thread if you want to collaborate on that, I guess? It seems too much for one email.</div>

<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Also, any thought as to whether it'd be possible to run this through a<br>
single Thingy? I'm picturing eg little plastic stubs touching the<br>
actual board surface; those stubs underneath are connected to fiber<br>
optic, which has a splitter - one end taking input from individual<br>
LEDs, the other end going to a photodiode array for reading. But I<br>
have no idea if this kind of simultaneous i/o split is even possible.</blockquote><div><br></div><div>The approach I have in mind involves multiplexing sensors that are all being polled by a single Thingy. I've made 12 inputs at a time work. Not 19^2, but they needn't all be on the same processor.</div>

<div><br></div><div><jazzhands></div><div>There's another possibility in gaining an image of a whole board at a time, using a wide-angle lens not a fiber-optic setup, and doing some edge detection.. uh.. stuff . This is how the homebrewed multitouch table at C-Base works, except it's using IR spectrum instead of visible. I know basically nothing about camera image processing! Yay.</div>

<div></jazzhands> </div><div> </div><div><div class="im">>> Or you could hack up a two-color monome with the buttons at crosses.<br><br></div>>That looks pretty neat equipment. Though expensive and sold out, and<br>

not available in 19x19. ;-)</div><div><br></div><div>Sparkfun sells <a href="https://www.sparkfun.com/products/7835">https://www.sparkfun.com/products/7835</a>, which is readily chainable, 97% as nice, and 100% as much fun to poke.</div>

<div><br></div><div>Ari </div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">
> Daylight might ruin this whole plan; choosing a photodiode responsive to<br>
> only a certain spectrum would help. I recommend NOT choosing the IR spectrum<br>
> to play with.<br>
<br>
</div>*nod* Ideally I'd like it to work in a reasonably wide range of<br>
lighting conditions; the display part might need to be pretty bright<br>
to be seen though, especially when diffused as a halo.<br>
<br>
On the up side, if the stone is covering the Thingy/photodiode, then<br>
that blocks most outside light. Worst case scenario, it shouldn't be<br>
too hard to distinguish 'stone' from 'no stone'. I don't know if my<br>
"shoot light at it and read the reflectance through the same Thingy"<br>
idea is viable, but at least the presence of the stone creates a<br>
relatively controlled situation.<br>
<br>
Though hm, it wouldn't necessarily be *directly* covering the Thingy<br>
('cause go stones have a relatively small contact surface, and move<br>
around a bit).<br>
<br>
This is also potentially a method for playing chess or the like, with<br>
the same board. You'd need to cover the pieces' bases with something,<br>
but then you get to control what that something is for optimal<br>
distinctiveness.<br>
<div class="im"><br>
> It might not work at all, but little cones of light spilling from the edges<br>
> of stones sounds like a lovely game.<br>
<br>
</div>*nod* I imagine one could make all sorts of neat variants if this<br>
works. First getting it to work, though...<br>
<div class="im"><br>
> Or you could hack up a two-color monome with the buttons at crosses.<br>
<br>
</div>That looks pretty neat equipment. Though expensive and sold out, and<br>
not available in 19x19. ;-)<br>
<span class="HOEnZb"><font color="#888888"><br>
- Sai<br>
</font></span></blockquote></div><br>